The First Finding of Foliar Flora Fossils in the Section of Cenozoic Deposits of Sardakh-Sise Island (Lena River Delta)

The first findings of well-preserved foliar flora ( Platanus sp., Alnus sp., Fagus sp., Salix sp., and Magnolia sp.) have been recovered from the Late Cenozoic (Neogene) deposits on Sardakh-Sise Island, in the Lena River delta. The findings, which also include remains of coniferous wood, are hosted in ferruginized sandstones at the base of the section. The floral composition suggests that mixed forests incorporating coniferous, broad- and small-leaved deciduous trees, and shrubs (moderate and subtropical thermophytes) grew in this area. The deposits contain foliar flora could forms in the Early–Middle Miocene, not in the Pliocene as is presently believed. Most likely, the basal conglomerates and sandstones of the Sardakh-Sise Island section refer to the Urasalakh Fm. The finding site of Neogene foliar flora on Sardakh-Sise Island is now the northernmost location in Eurasia.